Electric change-speed gearing for automobiles.



T. VON ZWEIGBERGK.

ELECTRIC CHANGE SPEED GEARING FOR AUTOMOBILES.

APPLICATION FILED JUNE 2!, I916.

1,292,218. Ptented Jan. 21,1919.

4 SHEETS-SHEET I.

T. VON ZWEIGBERGK.

ELECTRIC CHANGE SPEED (BEARING FOR AUTOMOBILES.

APPLICATION FILED JUNE 21. i916- Patented Jan. 21, i919.

4 SHEETSSHEET 2.

//v vE/vTox? fizz; awn/Z01 T. VON ZWEIGBERGK.

ELECTRIC CHANGE SPEED GEARING FOR AUTOMOBILES.

APPLICATION FILED JUNEZI. 1916.

1,292,218. Patented Jan. 21,1919.

4 SHEETS- SHEET 3.

T. VON ZWEIGBERGK.

Patented Jan. 21, 1919.

4 SHEETSSHEE 4.

ELECTRIC CHANGE-SPEED GEARING FOR AUTOMOBILES.

Specification of Letters Patent.

Patented Jan. an, acre.

Application filed. June 21, 1916. Serial No. 104,839.

To all whom it may concern Be it known that I, THoRs'rEN VON ZWEIG- BERGK, a citizen of the United States, residing at Lancaster, in the county of Lancaster, England, have invented a certain new and useful Improvement in Electric Change-I separable contacts. Other objects areto reduce the weight and render the mechanism more compact, as well as to increase the general efficiency of the device andv the flexibility of its control. Though my invention is capable of various uses, the above noted characteristics make it especially useful on automobiles, for changing the amount or direction of speed between an internal combustion engine and the driving wheels.

Broadly speaking, my invention comprises a pair of rotary armatures and a single Sta-- tionary field with its winding terminating at brushes for the two armatures, one armature bein connected directly with the engine sha t and the other being connected with it through epicyclic gearing which is also connected with the propeller shaft. Thus one armature may generate a counter electro-motiveforce reacting on the other to a degree controlled by the shifting of the commutator brushes, and the amount of retardation or acceleration thus given to the epicyclically connected armature determines the speed transmitted from the engine shaft to the vehicle shaft.

I find that by making one of the armatures hollow and mounting it concentrically about the other, and placing between the two a stationary field structure facing in two directions, I can reduce the weight of the mechanism and make it extreme y compact, both of which characteristics are. particularly desirable in automobile work.

I prefer to place the commutators at the opposite ends of the respective. armatures and carry the brushes on rotatable members which are ounted on the frame structure and readily 'shiftable about the axis. A pair ries.

of brushes is provided for each commutator, one brush of each commutator being a terminal of the field winding (which may be a series winding about different pole pieces), so and the remaining brushes of the two commutators being connected together so that both armatures andthe field are in one se- In such construction the only control necessary is the shifting of the commutator brushes to change from the off position through various speeds to maximum speed or to reverse. This will all be clear from the description of an illustrative embodiment of my invention contained in the drawings 70 hereof. It is to be understood, however, that many modifications may be made therein without departing from 'my invention, as summarized in the claims.

In the drawings, Figure 1 is a side elevation, partly sectional, of my invention embodied in a form suitable for automobile. use; Fig. 2 is a transverse section thereof on two planes, one indicated by the line 22 on Fig. 1, and the other by the line 2 so Fig. 3 is a sectional side elevation of the epicyclic gearing and adjacent parts shown in Fig. 1, this view showingin full elevation several of the parts which appear in section in Fig. 1; Fig. 4 is a cross section on the '85 line 44: on Fig. 1, looking toward the right and showing means for shifting the brushes for the commutator of the internal armature; Figs. 5 and 6 are cross sections of the epicyclic gearing, as indicated respectively by the lines 5-5 and 66 of Fig. 3, looking toward the right. Figs. 7 to 12 inclusive are diagrams illustrating the positions 3 of the brushes for accomplishing various speed results, as there explained.

In the'particular embodiment shown, 10, 11 and 12 indicate parts of a stationary casing, which are rigidly connected together and house mechanism about to be described. The part 10 of this casing extends to the left of this figure and may there house a prime mover (for example, an internal combustion engine), not shown. Immediately at the left of the change speed mechanism the casing has a transverse partition 13, which carries 106 a central bearing 14, for the engine shaft 20, which drives mechanism now to be described.

On the right hand end of the engine shaft 20 is shown a head 21, to which is bolt- 110 ed a disk-like casting 22, clamped to which (by bolts and a clamping ring 23), is a the external armature.

ring member 24, constituting the frame .of

Mounted on the inner face of this ring member 2a are annular laminations 25. These laminations are shown as clamped in position by a ring member 27, which is locked in place by a ring 28, threaded into the end portion of the armature frame 24.

The armature conductors 30 lie in notches in the inwardly facing portion of the laminations 25. At their doubled ends these conductors are housed by the ring 27' and the ring 29 secured to and projecting inwardlyfrom the end of the ring 27. At their other ends the armature conductors extend beyond the ring 24 through openings therein, where they are connected to radial conductors 32 projecting from commutator bars 83. These commutator bars are shown as mounted on insulation carried by a projecting portion 35 of the casting 22, and by a ring 36 bolted shaft 52 is shown as rigidly clamped to a suitable head 53, which may be secured to the propeller shaft of a vehicle or other member to be driven. For convenience I will hereafter'refer to the shaft 52 and its rigidly connected parts, as the propeller shaft.

The propeller shaft is shown as mounted in a ball bearing 55, carried in the frame casing 16, rigidly secured to the casing portion 12. There is also shown a suitable thrust bearing 56 between these casings and the propeller shaft, the bearing being held between a head 57 on the propeller shaft and the nut 58 screwing onto the body of the shaft.

Surrounding the driven shaft 42 and adjacent to its right-hand end is a sleeve 60,

which extends into and is rigidly connected with a longer sleeve 61, which carries the internal armature. These sleeves,- the driven shaft. 42, and the propeller shaft 52, are mutually connected by epicyclic or planetary gearing. This gearing, which will be specifically described hereinafter, is such that if the sleeves are held stationary, rotation of the shaft 42 transmits-rotation to the propeller shaft; while, on the other hand, if the propeller shaft is stationary, rotation in the opposite direction is transmitted from the shaft 42 to the sleeves and internal armature.

suitable wi-ndings81 about them.

rigidly mounted on this sleeve is a casting 66, which, with a casting 6'7 bolted to it, carries, suitably insulated, the commutator "73. With this commutator connect armature conductors 70, which occupy notches in the laminations. There are only half as many of these armature conductors as there are conductors in the external armaturethe reason for which will be hereinafter given.

Between the internal and external arma tures is a. stationary field structure which coacts with both armatures. structure comprises a stationary ring-like frame carrying laminated pole pieces and The frame consists of two castings 83 and 84, in the form of rings having cup-like recesses to house the windings, and, between the laminations, secured together by bolts 82. The casting 84 is continued to the right, where it is rigidly bolted, as at 87, to the frame casting 12. The lower portion of this casting 84 is made segmental and constitutes the part of the stationary frame heretofore designated 11. The upper portion comprises parallel arms 85.

The casting 83, which, as above stated. is bolted to the casting 84, and clamps the field cores, also serves the purpose of supporting a bearing for the sleeve 61. To effect this, the casting extends around the end of the armature conductors 70. and then inwardly, forming a seat for the ball bearing 90. This casting also carries an oil guard 91, engaging the shaft 12. The other bearing for the sleeve 61, which is shown as the ball bearing 93, is mounted in a stationary disk-like member '91, which is rigidly I connected to the genera] frame casing, being preferably clamped between the members 11, S5 and the casting 12.

The brushes for the two commutators are shifta-ble thereon to effect the desired control. As shown, there are two brushes for each armature. One of the brushes 100. for the armature 33, is shown in Fig. 1. This. and a corresponding brush (not shown). are mounted in brush holders 101 rigidly st cured to a rotative ring 102, which is mounted on the stationary frame 13. Suitable flexible conductors, indicated at 103, mounted in a recess in this ring, are connected with the respective brushes. The ring may be given a rotative movement. which in the present instance may be about a third of a rotation, by means of an arm 105, fixed to the ring and projecting outside of the casing. The brushes 110 for the commutator 73 of the internal armature, are similarly carried by brush holders 111, rigidly project- This field ane,

ing from a ring 112. This ring is formed to house the terminal lines 113 leading to the respective brushes. A projecting arm 115 furnishes means for swinging the ring, which, in this case, need be for only about a sixth of a rotation, as hereinafter explained. Any suitable operating means may be connected with the arms 105 and 115, as hereinafter explained, to furnish the means for controlling the speed and the direction of rotation transmitted to the propeller shaft. N

1 will now describe the planetary gearing mutually connecting the driven shaft 42. the propeller shaft 52, and the internal armature, through the sleeves 60'61, this construction being shown in Figs. 1, 3, 5 and 6.

Rigidly secured to the propeller shaft is a cage 120 for the planetary gearing. This cage is in the form of a cylindrical box having a portion of its cylindrical wall open. The fiat wall opposite the connection to the propeller shaft is shown as having a bearing on the armature sleeve 61, this hearing being Shown at 122. Through this bearing, the

sleeve 61 and the bearing 93, the strain is taken to the stationary frame plate 94. Mounted in the opposite walls of the cage 120 and extending parallel with the axis thereof, is a stationary arbor 124,0n which is rotatively mounted the pinion 125, rigid with which-is the gear wheel 126, which is shown as having twice the number of teeth of the pinion. The gear 126 meshes with a pinion 127 formed on the sleeve 60 and thus rigid with the armature. The pinion 125 meshes with an idler gear 128, which is carried on the stationary arbor 123, mounted in the cage 120. This idler 128 meshes with a pinion 129 which is keyed to the driven shaft 42.

It results from the above construction that if the internal armature is held sta- 'tionary, and the driven shaft 42 rotated, the

propeller shaft will be-driven in the same direction as the driven shaft 42, but at two thirds the speed. If, on the other hand, the propeller shaft be held stationary and the driven shaft rotated, the internal armature will be revolved in the opposite direction from the driven shaft, at'twice the speed.

In further explanation of this result, it may be stated that as the pinion 129 is rigid on the shaft 42, it makes a rotation for each rotation of the shaft, which, in this case, is also a rotation of the internal combustion engine shaft. This rotation of the pinion 1-29 is transmitted through the idler 128 to the pinion 125, which thus makes a rotation. As this pinion is rigid with the gear 126, it also must make a rotation. Now, as-

suming that the internal armature is stationary, the pinion 127 is stationary, and, accordingly, for the car 126 to rotate, it must travel bodily in t e direction of the engine shaft and roll around the stationary pinion 127; as this gear 126 has twice the periphery of that pinion, the gear will have to make two trips around the pinion for the gear to have a rotation on its own axis. As the gear 126 is rigid with the pinion 125, this means that one rotation is required of the pinion 125 about its own axis at the same time that it bodily travels two rotations about the axis of the shaft 42, (assuming always that the reaction pinion 127 is stationary). As the gearing between the pinion 125 and the pinion 129 on the shaft 42,'is without change of speed ratio or direction, it is evident that one rotation of the shaft 42 is necessary to give a rotation to the pinion 125 about its own axis, and two rotations of the shaft 42 are necessary to carry the planetary gearing at the sametime about the axis ofthe shaft for two rotations, the result being that three rotations of the shaft 42 result in two rotations of the propeller shaft when the reaction gear 127 on the armature shaft is stationary. In other words, under these conditions, each rotation of the engine shaft delivers twothirds of a rotation to the propeller shaft.

On the other hand, if the internal armature be free, and the propeller shaft held, the arbors 124 and 123 are stationary, and all the gears rotate on their own axes, instead of traveling. Accordingly, a rotation of the engine shaft, giving a rotation to the pinion 129, gives a rotation in the same direction and at the same speed to the pinion 125, which rotates the gear 126 1n the same direction, at twice the peripheral speed,

which rotates the pinion 127 in the opposite direction at twice the speed of the shaft 42. Accordingly, if the propeller shaft be held, the internal armature is rotated in the reverse direction to the driven shaft and at twice the speed thereof.

As the internal armature has half as many conductors as the external armature, it follows that, when the propeller shaft is stationary, the same-number of conductors cut lines of force in any given time at both the internal and external armatures, but in opposite directions. The windings of the armatures are such that in this opposed movement, one armature coacts with the field to constitute a generator and the other a motor, and as the. two armatures are in series with each other, the generator gencrates electromotivc force which is counter- &

Now, if the propeller shaft be free, and at the same time the internal armature be given a rotation different from twice the speed of the engine-shaft in a reverse direction, a composite speed is delivered to the propeller shaft, which may vary all the Way from nothing to a speed of more than that of the engine shaft. decrease in the speed of rotation of the internal armature in the reverse direction to the engine shaft, causes an increase in the speed of the propeller shaft; when the internal armature becomes stationary, the propeller shaft is rotating at two-thirds the speed of the engine shaft; then, if the internal armature be rotated in the same direction as the engine shaft, the speed of the propeller shaft is increased as the ar ature rotation increases. When the speed of the internal armature, rotating in the same direction as the engine shaft, is equal to that of the engine shaft, the whole planetary gearing rotates as a unit, and the propeller shaft rotates at the same speed as the engine shaft. If the speed of the internal armature in the same direction is increased above that of the engine shaft, the speed of the propeller shaft is also increased with relation to the engine shaft.

The external armature is wound with such relation to the field that the reaction of the armature will be equal to the action 1 of the field at all points of position of the give all desired variations of speed transmitted, as well as toreverse the direction of propulsion. l

\ Figs. 7 to 12 inclusive are diagrams of positions of the brushes for various speeds. It is to be understood that these are simply illustrative, since, as above explained, an infinite variety of speeds may be obtained. In these diagrams the two commutators (indicating the respective external and internal armatures), are designated, as heretofore, 33'and 73, respectively. Likewise the corresponding brushes are designated 100 and 110, and the field winding 81. The direction of rotation of the engine shaft, which is also that of the external armature, is indicated bythe arrow designated E, and the direction of rotation of the internal armature by the arrow I. C indicates the direction of current assumed to be flowing in the field winding 81.

I will refer first to Fig. 8, which diagram illustrates the position of-the brushes when the engineris running free and the car standing still, the propeller shaft being thus sta- That is to say, a

tionary and the internal armature rotating at twice the speed of the engine shaft, and in the opposite direction thereto. v The brushes 100 of the external armature, as well as the brushes 110 of the internal armature,

shifted toward the left to the center of the 'poles, as shown in Fig. 9, both armatures coact with the field to become active electric machines. The series field being originally charged'with current in the direction of the arrow C, this will allow only'the generator which generates current in this direction to build up. .The windings of the armatures being so made that when the internal armature rotates in the opposite direction to the external, it becomes a generator, the internal machine now generates an electromotive force tending to send current in the direction of the arrow' C, and the external machine becomes a motor sending a counter electro-motive force against the internal armature. i

As the internal armature is revolved through the gearing at twice the speed of the external, while the external has twice the number of conductors of the internal, the generated voltage equals the counter electromotive force, and no current flows. If, however, the brushes 100 are moved slightly farther to the left,wh ile the brushes 110 of the internal armature are left in the same position, the counter electro-motive force of the external armature will be reduced and the generated voltage will overtake the counter electro-motive force, and current will flow in the direction of the arrow As the brushes 100 are moved still farther to the left, the internal generator will, to a continuously greater extent, overtake the counter electro-motive force of the external armature, until the position shown in Fig. 10 is produced, where the brushes 100 have been movedbetween the pole pieces and the internal generator becomes practically short circuited, as no counter electro-motive force is then generated in the external armature.

Considering now what takes place in the gearing, we find that while the internal armature acts as a generator, it tends to stop, and, in doing so, reacts on the epicyclic gearing to cause movement to be transmitted to the propeller shaft, while the external armature operates to help the engine.

In the embodiment shown the internal armature is geared two to one to the driven shaft and hence will produce an effective reaction equivalent to twice the torque of the-internal armature. The external armamaximum voltage.

ture being directly connected with the engine has a torque equivalent to that of the engine. We therefore have a total torque equal to twice the engine torque (its own torque and the external armature torque) plus twice the internal armature torque.

This may give a most efiective power for starting the automobile and getting under way.

In Fig. 10, we find that the internal armature will rotate very slowly, and, therefore, nearly two-thirds of the full speed is obtained. If we now move the brushes 100 still farther toward the left, we find that the externalarmature will act as a generator, the current which it generates being in the direction of the arrow C and therefore enabling it to build up. The internal armature, which has been gradually slowed down in its reverse rotation until it momentarily stops now becomes a motor and commences to rotate in the same direction as the engine and external armature.

In Fig. 11 the brushes have been moved half way toward the center of the poles, and, since the external armature has twice the number of conductors of the internal, the internal armature, under these conditions, rotates at the same speed as the engine. Therefore, at this point the whole epicyclic gearing rotates as one body with the engine, and full speed (i. e. propeller shaft rotation equal to engine shaft rotation), is'obtained.

The so-called full speed, obtained by the position of the brushes shown in Fig. 11, takes place before these brushes have been moved far enough to give the maximum voltage, and, accordingly, an over-speed is still obtainable. This is illustrated in Fig. 12,

where the brushes 100 have been moved to I give the maximum voltage, and the speed of the internal armature becomes twice that of the engine speed, but in the same direction, and the action through the gearing gives extra speed, of say thirty-three'per cent. to the propeller shaft. This feature is some times desirable in enabling the car to speed up on a level road, or to spurt quickly.

In shutting off the power it is only necessary to move the brushes 100 to thefoif position shown in Fig. 8. Nothing will happen to either armature during this movement, as the external armature'is unable to generate after the brushes have been moved toward the right, and the internal armature cannot generate until it commences to rotate backwardly. Before doing so, it, of course, reaches the OE position.

' In order to. reVerse the direction of movement transmitted to the car, I move the brushes 100 from the off position toward the right, to the middle of the poles, thereby making the external armature generate a The brushes 110 of the internal armature are not moved to maximum voltage position, but say only half way. This condition is indicated in Fig. 7. The result is that the internal armature revolves in the opposite direction at a higher speed than two to one. As the two-to-one speed is the equilibrium for the epicyclic gearing, the higher speed ratio will cause a slow rotation to be transmitted in a reverse direction to the propeller shaft.

It will be seen from the above description of selected speeds that by the simple act of shifting the brushes of the external armature through perhaps a third of a rotation, and the brushes of the internal armature a considerably less distance, I obtain any de- -sired speed or direction of transmitted up the internal brushes and return both sets to the off position shown in Fig. 8. A farther reverse movement of such operat- 1ng lever,or a different lever if desired,

could carry the brushes from the OE position into the reverse position shown in Fig. '2.

Having thus described my invention, what I claim. is:

1. In a change speed gearing, the combination of two armatures, a common field therefor, a driving member connected with one armature, a driven member, and epicycle gearing connecting the other armature with both driving and driven members.

2. In a change speed gearing, the combination of two armatures, a common. field therefor, brushes for the two armatures constituting terminals from the field, a driving member connected with one armature, a

driven member, and epicyclic gearing connecting the other armature with both driving and driven members, such gearing including a reversing idler.

3. In a change speed gearing, the combination of two armatures, a driving device connected with one armature, a driven, de-

vice, and epicyclio gearing carried by the armature, a driven device, and epicyclic gearing carried by the driven device and connected with theaother armature and the driving device.

5. The combination of two armatures having independent commutators, a field structure having a series field winding terminating at brushes on the respective commutators, means for shifting the brushes on each commutator independently of those on the other, a driving device connected with one armature, a driven device, and epicyclic gearing mounted on the driven device and geared with the other armature and with the driving device.

6. In a change speed gearing, the combination, with stationary field means facing in opposite directions, of two rotatable armatures cooperating therewith, a driving member connected with one armature, a driven member connected with the other armature, and epicyclic gearing connecting the other armature with both the driven member and driving member.

7. In a change speed 7 earing, the combination of a stationary eld structure provided with a series Winding, two rotatable armatures having their windings in series with each other and with the field winding, a driving member connected with one armature, a driven member connected with the other armature, and epicyclic gearing carried by the driven member and geared with the driving member and the other armature.

8. The combination with field means, of-

two armatures, a driving member connected with one armature, a driven member, and gearing connecting the other armature with both the driving and driven members, said gearing being arranged to give its connected armature a different speed of rotation from the speed given to the other armature, the number of conductors of the two armatures having the inverse ratio of the said speeds transmitted to said armatures.

9. The combination of an internal armature, an external armature about the same, an interposed stationary field structure between the two armatures, a driving member connected with one armature, a driven member, and epicyclic gearing connecting the other armature with both the driving and driven members.

10. The combination of an internal armature, an external armature about the same, an interposed stationary field having its winding in series with both armatures, a driving member connected with one armature, a driven member, and epicyclic gearing connecting the other armature with both the driving and driven members.

11. The combination, with internal and external armatures, of a stationary field interposed between them and coacting with both of them, a driving member connected 1,2.ea,21s

with one armature, a driven member, epicyclic gearing carried thereby and geared with the driving shaft and with the other armature, said armatures having independent commutators, brushes on the respective commutators forming terminals of the field winding, and means for shifting the brushes of the two commutators independently of each other.

12. The combination of an internal armature, an external armature about the same, an interposed stationary field between the two armatures, a driving member connected with one armature, a driven member, and epicyclic gearing connecting the other armature with both the driving and driven members, said gearing being ar-' ranged to give its connected armature a different speed of rotation from. the speed given to the other a-rmature,'the number of conductors of the two armatures having the inverse ratio of the speeds transmitted from the driving member to the respective armatures.

13. The combination, with an interposed field, of an external armature therefor, an

internal armature coacting with the same field, a driving member connected with the external armature, a driven member, epicyclic gearing connecting the internal armature with both the driving and driven mem bers and enabling the internal armature to rotate at a multiple of the driving speed when the driven member is stationary, the number of armature conductors of the external armature being this same multiple of those of the internal armature. v

14. The combination with an interposed field, of two armatures one surrounding the other, a driving device connected with the external armature and having a shaft extending freely into the internal armature, a driven member, anv epicyclic gearing mounted on said driven member and geared through anidler with said shaft and directly with the internal armature. 15. In a change speed gearing, the combination of a driving shaft, a driven shaft and a propeller shaft all alined, two armatures, one surrounding the other, the outer armature being connected with the driving shaft and the inner armature surrounding the driven shaft, and epicyclic gearing surrounding the driven-shaft and carried by the propeller shaft and geared to the said driven shaft and to the latter armature.

16. The combination with a prime mover and a device to be driven, of an interposed electric change speed gearing comprising a same winding on the field, means rigldly 13 meagre connecting the external armature with the prime mover, a shaft within the internal armature connected with the prime mover, and epicyclic gearing connecting said shaft with both the internal armature and the device to be driven.

17. The combination, with an interposed field structure, of internal and external armatures coacting therewith, said armatures having commutators at their respectively opposite ends, brushes for said commutators, means for shifting the brushes, a shaft extending through the internal armature, a prime mover connected with both the external armature and one end of said shaft, a device to be driven opposite the other end of said shaft, and planetary gearing adjacent to that end of the shaft and having its planet shaft carried by the device to be driven and two rigidly connecting gears on the planet shaft, one of which meshes with a gear on the internal armature and the other of which meshes with a planetary idler meshing with a gear on the shaft first mentioned.

18. The combination with an interposed field, of an external armature therefor, an internal armature coacting with the same field, a driving member connected with the external armature and having a shaft within the internal armature, a driven member, and epicyclic gearing connecting the internal armature, the driven member and said shaft, and enabling the internal armature to rotate at a multiple of the driving speed when the driven member is stationary, the number of armature conductors of the external armature being the same multiple of those of the internal armature.

19. The combination with a driving device, of a shaft driven thereby, a sleeve surrounding said shaft, a main stationary, frame carrying bearings for said sleeve, a device to be driven alined with said shaft, planetary gearing between said shaft, said driven device and said sleeve, said planetary gearing having hearings in the stationary frame and on said sleeve, an internal armature rigidly mounted on said sleeve, an external armature surrounding the internal armature, and a stationary field structure between the two armatures and supported by said main frame.

In testimony whereof, I hereunto afiix my signature.

'fHURSTEN VON ZWEIGBERGK.

MARION E. CLOUD, 9 

